Generally, the present application relates to flameless candle circuits. Particularly, the present application relates to flameless candle circuits that cause light emitting diode(s) (“LED”) to generate light in two or more different modes.
Flameless candles may include a circuit (e.g., one or more circuits or sub-circuits) that drives one or more LEDs to generate light. Such a circuit may cause an LED to flicker, thereby creating an illusion of a flickering flame. The circuit may also include a timer that can automatically turn the LED off after a period of time. The timer may also turn the LED back on after another period of time.
FIG. 1 shows a schematic illustration of a prior art flameless candle circuit 100. The circuit 100 has a double-pole triple-throw switch (“2P3T switch”) 110, a battery 120, an application specific integrated circuit (“ASIC”) 130, an oscillator 140, an LED 150, and a resistor 160.
The circuit 100 generally operates in the following manner. The ASIC 130 has an output that intermittently provides a current through the resistor 160 and the LED 150. The current causes the LED 150 to emit light. By pulsing the current, it is possible to cause the LED 150 to flicker. An oscillator 140 regulates the timing functions of the ASIC 130. The ASIC 130 has an input that can be high or low. Depending on the state of the input, the ASIC 130 operates in two modes. One mode constantly drives the LED 150 causing it to flicker. The other mode drives the LED 150 for a period of time and then stops. After another period of time, the ASIC 130 will again drive the LED 150 and the cycle will repeat.
Power to the circuit 100 is provided by the battery 120. The selected mode of operation is determined by the state of the 2P3T switch 110. The 2P3T switch 110 has three different positions. When the 2P3T switch 110 is in the first position, the circuit 100 is turned off. Specifically, the negative terminal of the battery 120 is disconnected from ground, causing it to float. Consequently, current can no longer flow to through the battery 120 thereby shutting off the power to the ASIC 130.
When the 2P3T switch 110 is in the second position, the circuit 100 is turned on. Specifically, the negative terminal of the battery 120 is connected to ground, thereby allowing current to flow through the battery and provide power to the ASIC 130. Furthermore, the ASIC 130 is configured to provide a signal through the output to flickeringly drive the LED 150. Additionally, a high signal is applied to the input of the ASIC 130. This causes the ASIC 130 to recognize that a timer should be implemented. Accordingly, the ASIC 130 will shut off the LED 150 after a period of time and then back on after another period of time.
When the 2P3T switch 110 is in the third position, the circuit 100 is turned on. Specifically, the negative terminal of the battery 120 is connected to ground, thereby allowing current to flow through the battery and provide power to the ASIC 130. Furthermore, the ASIC 130 is configured to provide a signal through the output to flickeringly drive the LED 150. Additionally, a low signal is applied to the input of the ASIC 130 (for example, there may be a pull-down resistor on the input line). This causes the ASIC 130 to recognize that no timer should be implemented. Accordingly, the ASIC 130 will constantly and flickeringly drive the LED 150.
The circuit 100, however, requires the relatively expensive 2P3T switch 110. In addition to the part cost, the 2P3T switch 110 requires relatively complex wiring, thereby increasing material costs again. Furthermore, such a component may take up more space on a printed-circuit board or in other dimensions. Therefore, a simplified, compact, and less-expensive circuit is needed.